An alkane has a $C/H$ ratio (by mass) of $5.1428$. Its molecular formula is

The sulphate of a metal $M$ contains $9.87\%$ of $M$. This sulphate is isomorphous with $ZnSO_4 \cdot 7H_2O$. The atomic weight of $M$ is (in $.3$)

An organic compound is estimated through the Dumas method and is found to evolve $6$ moles of $CO_2$,$4$ moles of $H_2O$,and $1$ mole of nitrogen gas. The formula of the compound is

Reduction of $7.2 \, g$ of a metal oxide yields $6.4 \, g$ of the metal. If the atomic mass of the metal is $128 \, g/mol$,the formula of the oxide is .....

$A$ substance contains $38.8\% \, C$,$16\% \, H$,and $45.2\% \, N$. What is the empirical formula of the substance?

An organic compound weighing $500 \ mg$ produced $220 \ mg$ of $CO_2$ on complete combustion. The percentage composition of carbon in the compound is $..........\%$. $(nearest \ integer)$ $(Given \ molar \ mass \ in \ g \ mol^{-1} \ of \ C: 12, O: 16)$